Water heating and other heat-transfer apparatus



Dec. 8, 1931. .1. HICKEY ET AL WATER HEATING AND OTHER HEAT TRANSFER APPARATUS Filed April 30, 1931 Patented Dec. 8, 1931 UNITED STATES PATENT OFFICE JOHN HIGKEY AND WILLIS M. WRIGHT, OF NEW HAVEN, CONNECTICUT, ASSIGNORS TO THE NATIONAL PIPE BENDING COMPANY, OF NEW HAVEN, CONNECTICUT, A

CORPOR "LTION WATER HEATING AND OTHER Application filed April 30,

This invention relates to an improvement in heat-transfer apparatus, and while primarily designed for heating water, it is available for many other uses where it is desired to either add or subtract heat from a fluid,

etc.

The main object of our present invention is to provide at a relatively-low cost for manufacture, a simple and reliable heattransfer apparatus constructed with particular reference to superior efficiency.

With the above and other objects in view as will appear from the following, our invention consists in a heat-transfer apparatus having certain details of construction and combinations and arrangements of parts as will be hereinafter described and particularly recited in the claims.

In the accompanying drawings:

Fig. 1 is a View partly in side elevation and partly in vertical longitudinal section of a water-heating apparatus embodying our invention;

Fig. 2 is an end view thereof;

Fig. 3 is a broken detail sectional view taken on the line 33 of Fig. 1, but on a larger scale;

Fig. 1 is a top or plan view of the tubeassembly detached;

Fig. 5 is an end view thereof looking toward. the tube-plate; and

Fig. 6 is a transverse sectional view taken on the line 6-6 of Fig. 4, but on a larger scale.

For the illustration of our invention we have chosen herein a water-heating apparatus including a horizontally-arranged cylindrical storage-tank 10 consisting in the main of a tubular body 11 and complementary convex heads 12 and 13, and resting, adjacent each of its respective opposite ends, upon supports 14 and 15.

Radially connected by means of a flangefitting 16 to the underside of the body 11 of the storage-tank adjacent the head 13 thereof, is a cold-water inlet-pipe 17 through which cold water is fed into the interior of the said tank.

For the purpose of drawing off a supply of hot water from the tank 10, we provide a HEAT-TRANSFER APPARATUS hot-water outlet-pipe 18 radially projecting from the upper surface of the body 11 adjacent the head 12 and secured in place by means of a flange-fitting 19 in the usual manner of water-heaters.

Near its lower end, the convex head 12 is formed with a tubular extension 20 terminating in an outturned flange 21 between the outer face of which and the inner face of the outturned flange 22 of a heater-head 23, is a disk-like tube plate or tube assembly member 24 firmly anchored in place by bolts 25 extending through the same and through the flanges 21 and 22 aforesaid, as shown in Fig. 1 of the drawings.

The tube-plate 24% is formed with a series of perforations into which are extended the respective ends of a plurality of sets or series of U-shaped heater-tubes which will be presently described.

In the embodiment of our invention herein chosen for illustration, we employ four sets of heater-tubes respectively numbered 26, 27, 28 and 29, all of U-shaped form and having their respective reaches sloped as shown and their ends firmly anchored in perforations in the tube-plate 2 1, before referred to.

The outermost set of U-shaped tubes consisting, shown, of two (more or less) tubes 26 and 26 which for purposes of description, may be presumed to have an internal diameter of 1%. The said tubes 26 and 26 are longer than the remaining three sets of tubes, presently to be described, while the tube 26 is slightly longer than the tube 26 and both of the said tubes extend through a supporting-plate 30 which serves to prevent them from sagging and vibrating. The said supporting-plate is provided with a pair of complementary adjustable legs 31 and 32 resting upon the inner surface of the body 11 of the tank 10.

The next set of tubes 27 consisting of three (more or less) U-shaped tubes 27*, 27 and 27 nest, so to speak, within the set of U- shaped tubes 26 before referred to and for purposes of description may be presumed to have an internal diameter of 1 The said tubes, just referred to, are smaller in diameter Serial No. 533,372.

in internal diameter and in the spread of their respective reaches, and shorter in their lengths. For purposes of descrlptlon, each of the tubes comprising the set or series 28 may be considered as having an internal diameter of 1%.

The innermost set of tubes 29 comprises five (more or less) tubes 29 29 29, 29 and 29 which nest,in,turn, so to speak, within the set of tubes 28 just previously described,

with respect to which they are smaller in internal diameter and the spread of their re spective reaches, and shorter in their lengths. These tubes may be presumed to have an internal diameter of 1".

From the foregoing, it will be seen that the respective sets of tubes are so proportioned with respect to each other that those having the larger flow-areas are longer than those of smaller flow-areas, so as to more or less accurately proportion the radiating surfaces to the respective flow-areas to secure a higher degree of efficiency. In other words, a tube of large flow-area has a correspondingly large radiating surface and carries a larger body of heating-fluid, and is, therefore, .made longer to effect a proper transfer of heatunits in accordance with the individual flowcapacity of anygiven tube. V

The heater-head 23 before referred to, is formed with an inlet-passage 33 terminating in a flange 34 for the attachment of an inlet- I pipe and serves to feed a heating-fluid, such as hot water or steam, to the respective upper reaches of the tubes of each of the sets of U-tubes 26, 27, 28 and 29.

Similarly, an outlet-passage 35 connects with the lower reaches of the said U-tubes and terminates in a coupling-flange 36, providing for the attachment of an outlet-pipe. The inletand outletpassages referred to are separated by a partition 37. V

' Preferably, the inlet-passage 33 and the outlet-passage 36 will be connected to a steam-boiler below the water-line thereof so as to utilize the hot boiler-water as a heating medium though, if desired, steam or any otherheating medium maybe fed through the said passages for flow through the respective tubes, which flow is facilitated by the sloping character of the respective reaches of the sai d tubes. The upper or inlet-reach of each tube is, as shown, sloped'downwar-d toward its bend, while the lower or outlet reach thereof is sloped downward away from the said bend, as is clearly shown in Fig. 1 of the drawings. p r From the foregoing, it willbe seenthat by means of our invention, we have provided a heat-transfer apparatus in which a practically uniform relation is provided between the heating surfaces of the individual tubes and'their respective flow-areas which determines the volumetric fiow of the heating medium therethrough, this relation being attained by maintaining a predetermined ratio between the diameter and length of the individual tube. I a

We further provide, by this relationship betweenthe heating surfacesof the tubes and their respective flow-areas, an opportunity of distributing the heating surfaces through the entire length of the tank, which is vital in tanks of great length, as .by this means, the water in the entire tank is heated.

lVith the usual type of'heater element using a group of U-tubes', all of the same or substantially the same diameter, it has been impossible to maintain an efficient ratio between the heating surface and the flow-area, which difficulty has been overcome by differentiating the flow-areas of the respective sets of tubes to a degree more or less commensurate with their lengths.

Furthermore, the use of sloping or pitched tubes, in combination with thebefore mentioned-relation between the heating surface and flow-area, prevents the formation of air or water pockets in the tubes, insuring a freer and better circulation of the heating medium through the tubes and therefore a more efiieient transfer of heat.

It will be understood that the number and sizes of the respective sets of tubes, herein shown and described, are merely illustrative and may be varied largely to meet the exigencies of any given installation.

It will be further understood by thos skilled in the art that our invention may as sume varied physical forms without departing from our inventive concept and we, therefore, do not limit ourselves to the specific .embodiment herein chosen for illustration, but only as indicated in the appended claims.

We claim: I r

1. In a. heat-transfer apparatus, the combination with a tube-assembly member; of

a plurality of Ushaped tubesof difierent cross-sectional areas andlengt'hs secured to the said tube-assembly member; one or more of the tubes of greater cross-sectional area being longer in the length of its flow-passage 2":t than the flow-passage of the tube of lesser cross-sectional area; whereby an efiicient re lationship is provided between the radiatingsurfaces of the respective'tu-bes and their respective flow-areas. V

.2; In a heat-transfer apparatus, the combination with a tube-assembly member; of a plurality of U-shaped tubes ofdiiferent cross-sectional areas and lengths secured to the said tube-assembly member; one or more its of the tubes of lesser cross-sectional area being shorter in the length of its flowpassage and less in the span between its respective reaches than the tube of greater crosssectional area; whereby an eflicient relationship is provided between the radiating-surfaces of the respective tubes and their respective flowareas.

3. In a heat-transfer apparatus, the combination with a tube assembly member; of a plurality of U-shaped tubes of different crosssectional areas and lengths secured to the said tube-assembly member; one or more of the tubes of lesser cross-sectional area being shorter in the length of its flow-passages and less in the span between its respective reaches than the tube of greater cross-sectional area, and nested within the span of the tube of greater cross-sectional area and length; whereby an efiicient relationship is provided between the radiating-surfaces of the respective tubes and their respective flow-areas.

4. In a heat-transfer apparatus, the combination with a tube-assembly member; of a plurality of sets of U-shaped tubes secured to the said tube-assembly member and differing in the cross-sectional areas and lengths of their constituent tubes respectively; the individual tubes of the set of tubes of greater cross-section al area being longer in the length of their flow passages than the tubes making up a set of lesser cross-sectional area; where by an efiicient relationship is provided between the radiating-surfaces of the respective tubes and their respective flow-areas.

5. In a heat-transfer apparatus, the combination with a tube-assembly member; of a plurality of sets of U-shaped tubes secured to the said tube-assembly member and differing in the cross-sectional areas and lengths of their constituent tubes respectively; the individual tubes of a given set of tubes being arranged in substantially-h0rizontal alignment with each other and the individual tubes of the set of tubes of greater cross-sectional area being longer in the length of their flow-passages than the tubes making up a set of tubes of lesser cross-sectional area; where by an efficient relationship is provided between the radiating-surfaces of the respective tubes and their respective flow-areas.

6. In a heat-transfer apparatus, the combination with a tube-assembly member; of a plurality of sets of U-shaped tubes secured to the said tube-assembly member and differing in the cross-sectional areas, lengths and spans of their constituent tubes respectively; the individual tubes of a set of tubes of lesser cross-sectional area being shorter in the length of their flow-passages and less in the span between their respective reaches than a setof tubes of greater cross-sectional area;

whereby an eflicient relationship is provided between the radiating-surfaces of the respective tubes and their respective flow-areas.

7. In a heat-transfer apparatus, the combination with a tube-assembly member; of a plurality of sets of U-shaped tubes secured to the said tube-assembly member and differing in the cross-sectional areas, lengths and spans of their constituent tubes respectively; the individual tubes of a set of tubes of lesser crosssectional area being shorter in the length of their flow-passages and less in the span between their respective reaches than a set of tubes of greater cross-sectional area; a set of tubes of lesser cross-sectional area and length being nested within the span of a set of tubes of greater cross-sectional area and length; whereby an eflicient relationship is provided between the radiating-surfaces of the respective tubes and their respective flow-areas.

In testimony whereof, we have signed this specification.

JOHN I-IIGKEY. IVILLIS M. WRIGHT. 

